Could not instantiate Seam component: motorcycleCategService Problem
giannisapi Mar 10, 2009 11:43 AMHI all,
I am trying to learn seam with jsf hibernate ajax by creating a simple advert application.
I used seam gen in to create a new project and generate the entity classes (i already had tables in the database).
After this i am tryign to follow the seam hotel booking example
 in the online documentation and create a new action to search for soemthjing motorcycle category in my case
.
I have an action class called MotorcycleCategImpl which holds some actions. Code below:
package com.advert.sbeans;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import javax.ejb.Remove;
import javax.persistence.EntityManager;
import com.advert.ebeans.Motorcycle;
import com.advert.ebeans.Motorcyclecateg;
import com.advert.service.MotorcycleCateg;
import org.jboss.seam.ScopeType;
import org.jboss.seam.annotations.Destroy;
import org.jboss.seam.annotations.Factory;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Scope;
import org.jboss.seam.annotations.datamodel.DataModel;
import org.jboss.seam.annotations.security.Restrict;
import org.jboss.seam.framework.EntityQuery;
@Name("motorcycleCategService")
@Scope(ScopeType.SESSION)
public class MotorcycleCategImpl  extends EntityQuery<Motorcyclecateg> implements MotorcycleCateg {
     /**
      * 
      */
     private static final long serialVersionUID = 1L;
     private String searchString;
    private int pageSize = 10;
    private int page  = 2;
    @In
    private EntityManager entityManager;
    
    @DataModel
    private List<Motorcycle> motorcycleCats;
    
    @In
    private com.advert.ebeans.Motorcyclecateg motorcyclecateg;
  
     public void find() {
        page = 0;
        if (motorcycleCats != null) {
             motorcycleCats.clear();
        }
        queryMotorcycles();
    }
     
     @Factory("list")
     public Map<String,Integer> getList() {
          System.out.println("In-method getList");
          Map<String,Integer> list = new TreeMap<String,Integer>();
          list.put("one", 1);
          list.put("two", 2);          
          return list;
     }
     public void it(){          
          System.out.println("In-method it");
     }
     
    @SuppressWarnings("unchecked")
    public void queryMotorcycles() {
         motorcycleCats = entityManager.createQuery(
                "select * from motorcycleCateg")
                .setMaxResults(pageSize)
                .setFirstResult(page * pageSize).getResultList();
         
         
    }
    
    public String getSearchString() {
          return searchString;
     }
     public void setSearchString(String searchString) {
          this.searchString = searchString;
     }
     public int getPageSize() {
          return pageSize;
     }
     public void setPageSize(int pageSize) {
          this.pageSize = pageSize;
     }
     public int getPage() {
          return page;
     }
     public void setPage(int page) {
          this.page = page;
     }
     public List<Motorcycle> getMotorcycleCats() {
          return motorcycleCats;
     }
     public void setMotorcycleCats(List<Motorcycle> motorcycleCats) {
          this.motorcycleCats = motorcycleCats;
     }
     @Destroy
     public void destroy(){
          
     }
     @Remove
     public void remove (){
          
     }
}My entity bean is as follows: 
package com.advert.ebeans;
// Generated Mar 9, 2009 2:52:56 PM by Hibernate Tools 3.2.2.GA
import java.util.HashSet;
import java.util.Set;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
import org.hibernate.validator.Length;
import org.hibernate.validator.NotNull;
import org.jboss.seam.annotations.Name;
/**
 * Motorcyclecateg generated by hbm2java
 */
@Entity
@Name("motorcyclecateg")
@Table(name = "motorcyclecateg", catalog = "advert", uniqueConstraints = @UniqueConstraint(columnNames = "category"))
public class Motorcyclecateg implements java.io.Serializable {
     private Integer motorcycleCategPk;
     private String category;
     private Set<Motorcycle> motorcycles = new HashSet<Motorcycle>(0);
     public Motorcyclecateg() {
     }
     public Motorcyclecateg(String category) {
          this.category = category;
     }
     public Motorcyclecateg(String category, Set<Motorcycle> motorcycles) {
          this.category = category;
          this.motorcycles = motorcycles;
     }
     @Id
     @GeneratedValue(strategy = IDENTITY)
     @Column(name = "motorcycleCategPK", unique = true, nullable = false)
     public Integer getMotorcycleCategPk() {
          return this.motorcycleCategPk;
     }
     public void setMotorcycleCategPk(Integer motorcycleCategPk) {
          this.motorcycleCategPk = motorcycleCategPk;
     }
     @Column(name = "category", unique = true, nullable = false, length = 100)
     @NotNull
     @Length(max = 100)
     public String getCategory() {
          return this.category;
     }
     public void setCategory(String category) {
          this.category = category;
     }
     @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "motorcyclecateg")
     public Set<Motorcycle> getMotorcycles() {
          return this.motorcycles;
     }
     public void setMotorcycles(Set<Motorcycle> motorcycles) {
          this.motorcycles = motorcycles;
     }
}Now i have a simple xhtml page from where i am trying to call the find method from the MotorcycleCategImpl class (as done the seam documentation roughly).
My xhtml page searchMotorcycles is as follows:
<!DOCTYPE composition PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<ui:composition xmlns="http://www.w3.org/1999/xhtml"
    xmlns:s="http://jboss.com/products/seam/taglib"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:rich="http://richfaces.org/rich"
    xmlns:a4j="https://ajax4jsf.dev.java.net/ajax" 
    xmlns:a="http://richfaces.org/a4j"
    template="layout/template.xhtml"> 
     
     <ui:define name="body">
    
    <h:form id="searchCriteria">
    <fieldset> 
       <h:inputText id="searchString" value="#{motorcycleCategService.searchString}" 
                    style="width: 165px;">
         <a:support event="onkeyup" actionListener="#{motorcycleCategService.find}" 
                 reRender="searchResults" />
       </h:inputText>
        
       <a:commandButton id="findMotorcycles" value="find Motorcycles" action="#{motorcycleCategService.find}" 
                        reRender="searchResults"/>
        
       <a:status>
          <f:facet name="start">
             <h:graphicImage value="/img/spinner.gif"/>
          </f:facet>
       </a:status>
       <br/>
       <h:outputLabel for="pageSize">Maximum results:</h:outputLabel> 
       <h:selectOneMenu value="#{hotelSearch.pageSize}" id="pageSize">
          <f:selectItem itemLabel="5" itemValue="5"/>
          <f:selectItem itemLabel="10" itemValue="10"/>
          <f:selectItem itemLabel="20" itemValue="20"/>
       </h:selectOneMenu>
    </fieldset>
    </h:form>
    
    <a:outputPanel id="searchResults">
  <div class="section">
    <h:outputText value="No Hotels Found"
                  rendered="#{motorcycleCats != null and motorcycleCats.rowCount==0}"/>
    <h:dataTable id="hotels" value="#{motorcycleCats}" var="motorcyclecateg" 
                 rendered="#{motorcycleCats.rowCount>0}">
        <h:column>
            <f:facet name="header">Name</f:facet>
            #{hot.name}
        </h:column>
        <h:column>
            <f:facet name="header">Action</f:facet>
            <s:link id="viewHotel" value="View Hotel" 
                    action="#{motorcycleCats.selectHotel(motorcyclecateg)}"/>
        </h:column>
    </h:dataTable>
    <s:link value="More results" action="#{motorcycleCats.nextPage}" 
            rendered="#{motorcycleCats.nextPageAvailable}"/>
  </div>
</a:outputPanel>   
</ui:define>
     
</ui:composition>
Now the problem is that as soon i try to load the above page i get the following error:
Could not instantiate Seam component: motorcycleCategService 
Any help would be appreciated. Find the stack trace below:
org.jboss.seam.InstantiationException: Could not instantiate Seam component: motorcycleCategService at org.jboss.seam.Component.newInstance(Component.java:2106) at org.jboss.seam.Component.getInstance(Component.java:1988) at org.jboss.seam.Component.getInstance(Component.java:1950) at org.jboss.seam.Component.getInstance(Component.java:1944) at org.jboss.seam.Namespace.getComponentInstance(Namespace.java:55) at org.jboss.seam.Namespace.getComponentInstance(Namespace.java:50) at org.jboss.seam.el.SeamELResolver.resolveBase(SeamELResolver.java:166) at org.jboss.seam.el.SeamELResolver.getValue(SeamELResolver.java:53) at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:53) at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:72) at org.jboss.el.parser.AstIdentifier.getValue(AstIdentifier.java:44) at org.jboss.el.parser.AstValue.getValue(AstValue.java:63) at org.jboss.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186) at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:71) at javax.faces.component.UIOutput.getValue(UIOutput.java:184) at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:201) at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:284) at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:154) at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:861) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:946) at javax.faces.render.Renderer.encodeChildren(Renderer.java:148) at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:837) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:936) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:942) at com.sun.facelets.FaceletViewHandler.renderView(FaceletViewHandler.java:592) at org.ajax4jsf.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:108) at org.ajax4jsf.application.AjaxViewHandler.renderView(AjaxViewHandler.java:196) at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:109) at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:100) at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:266) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83) at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40) at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90) at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64) at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45) at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:177) at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:267) at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:380) at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:507) at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56) at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:58) at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) at org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53) at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446) at java.lang.Thread.run(Unknown Source) Caused by: org.jboss.seam.RequiredException: @In attribute requires non-null value: motorcycleCategService.motorcyclecateg at org.jboss.seam.Component.getValueToInject(Component.java:2297) at org.jboss.seam.Component.injectAttributes(Component.java:1703) at org.jboss.seam.Component.inject(Component.java:1521) at org.jboss.seam.core.BijectionInterceptor.aroundInvoke(BijectionInterceptor.java:61) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) at org.jboss.seam.transaction.TransactionInterceptor$1.work(TransactionInterceptor.java:95) at org.jboss.seam.util.Work.workInTransaction(Work.java:47) at org.jboss.seam.transaction.TransactionInterceptor.aroundInvoke(TransactionInterceptor.java:89) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:44) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) at org.jboss.seam.core.SynchronizationInterceptor.aroundInvoke(SynchronizationInterceptor.java:32) at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68) at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107) at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:185) at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:103) at com.advert.sbeans.MotorcycleCategImpl_$$_javassist_6.validate(MotorcycleCategImpl_$$_javassist_6.java) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.jboss.seam.util.Reflections.invoke(Reflections.java:22) at org.jboss.seam.util.Reflections.invokeAndWrap(Reflections.java:144) at org.jboss.seam.Component.callComponentMethod(Component.java:2211) at org.jboss.seam.Component.callCreateMethod(Component.java:2134) at org.jboss.seam.Component.newInstance(Component.java:2094)
 
    